Electric-circuit interrupter.



R. P. JACKSON.

ELECTRIC GIRCUIT INTERRUPTER. APPLICATION FILED MAR. s, 1906. RENEWEDJUNE15,1911.

1,018,167, Patented Jan.2,1912.

WITNESSES:

Q INVENTOR UNITED STATES PATENT onnrcn MY 1?. JACKSON, F WILKINSBURG,PENNSYLVANIA, ASSIGNOR To WESTINGHOUSE ELECTRIC & MANUFACTURING COMPANY,A CORPORATION OF PENNSYLVANIA.

ELECTRIC CIRCUIT INTERRUPTER.

Specification of Letters Patent.

Patented Jan. 2,1912.

- Application fiIed March 3, 1906, Serial 110.804,!)22. Renewed June 15,191i. Serial No. 633,35fi.

' To whom it may concern:

Be it known that I, RAY P. llncirson, a citizen of the United States,and a resident of Wilkinsburg, in the county of Alleghenyand State ofPennsylvania, have invented a new and useful Improvement in Electric-Circuit Interrupters, of which the following is a specification. 1

-, My invention relates to switches or interrupters for electriccircuits and has special reference tosuch switches as are adapted formultiple or sequential operation in the control of electric motors forvariable speed service. s

The object of my invention is to provide, in aninterrupter of the classabove specified, improved means for so regulating the operation of themovable contact member that the circuit may always be interrupted at apredetermined point, and'to reduce to a, minimum the resistance of thecircuit through the contacts when the switch is closed.

Electric vehicle motors of relatively large size' and capacity are oftencontrolled by groupsiof electro-pneumatically or electromagneticallyoperated switches and as these I switches effect the complete control ofthe motor circuits, they are necessarily subjected to particularlysevere service. Therefore it is specially, desirable to provide anexcellent contact between the movable and stationary-members of theswitch and to revent the maintenance of arcs at the points where thecircuits are interrupted in order to prolong the life and increase theefficiency of the control apparatus. In the prior art, acontact arm hasusually been hinge-connectedto a stationary terminal,

, and operated by a reciprocating rod which moved it into and out ofengagement with a suitable stationary contact terminal. In order toprevent injuries to the contact surfaces by the arcs which take placewhen the circuit is interrupted, the contact end, of the hinged arm hasoften been yieldingly supported so that, as the arm was moved away,theoontactterminal itself was given a rolling motion, thereby causingthe arcs to form between surfaces which were so ated when the switch wasclosed. With t is construction, although a good connection could bemaintained between the movable cont-act -member and the correspondingstationary.

contact member, the resistance of the circuit through the contact armwas materially increased by reasonof the yieldable connection betweenthe arm and its contact terminal and by reason ofthe hinge connection between the arm and the stationary terminal to, which it was attached.

By my present invention I retain all the desirable features of the priorart and materially reduce the resistance through the contact members byconverting the arm into a briclgln contact member which is normally helin engagement with two stationary contact terminals by relatively highpressure, thereby establishing a direct connection through the contactarm when the switch is closed. In order to so open the circuit as toprevent injury to the contact surfaces, I connect a flexible shuntbetween one of the stationary cont-act members and one end of thebridging arm, which carries the current temporarily during the openingand closing of the switch.

The single figure of the accompanying drawing is a sectionalv elevationthrough a single switch constructed in accordance with my invention.

Although I have shown a pneumaticallyoperated circuit interrupter, myinvention is not confined thereto slnce any convenient means may beemployed for operating the movable member.

Referring to the drawing, a bridging contact arm 1 is pivotally mounted,near its central point, upon one extremity of an actuating rod 2, theother extremity of which is connected to a pneumatically-operated piston3 that acts in opposition to a spring 4 and moves the arm 1 into and outof engagement with a stationary contact member 5. The piston 3 operateswithin a cylinder 7 which is supplied with fluid-pressure through avalve 8 that is governed by an elect-romagnet 9. A terminal member 10 isattached to one end of the contact arm 1 and engages a stationaryterminal 6 when the switch is closed, the extremities of these terminalmembers 10 and 6 being located in the airgap of a magnetic circuit whichis produced by a magnetizing coil 11 and which serves to extinguish anyarcs which-may occur at this point. The upper extremity of the rod 2 isconnected to the stationary terminal 5 by means of a link 12. Theextremity 13 of the armrl which projects be- 'yond the terminal 5, isbifurcated to engage a rod 14 having a nut 14: and a washer 15 to limitthe motion of this extremity of the arm in one direction. The rod 14:serves also as a guide for a spring 15 that is interposed between thefork 13 and a projection 16 on the stationary terminal 5. The link 12,and a flexible conductor 16, constitute shunt paths for the currentduring the opening and closing of the switch, while the arm itself isheld firmly in engagement with the stationary terminal 5 when the switchis in its closed position.

The limiting rod 14: is so arranged, in combination with the spring 15,that, as the switch is closed, the outer extremity of the terminal 10 isfirst moved into engagement with the outer end of the stationaryterminal 6, whereupon circuit is completed from the terminal 5 throughthe link 12 and the conductor 16, the arm 1 and the terminal 10 to theterminal 6, since the spring 15 holds the projection 13 of the arm 1 inits extreme position of separation. As the rod 2 acts still further, thespring 15 is compressed and the arm 1 is moved into direct engagementwith the stationary terminal 5 and the normal contact surface of theterminal 10 is moved into engagement with the corresponding surface ofthe terminal 6 so that circuit is thereafter completed from terminal 5directly through the arm 1 and the terminal 10 to the stationaryterminal 6. When the air pressure is exhausted from the cylinder 7, thespring 42 opens the switch and the same steps are passed through inopeningas in closing, except that they are accomplished in the reverseorder, so thatthe terminal 10 is held in engagement with the stationaryterminal 6 until the opposite extremity of the arm 1 is disengaged fromthe terminal 5 and the projection 13 has reached the limit of itsseparation as determined by the washer 15, the circuit being finallybroken at the outer extremities of the terminals 6 and 10, which, ashereinbefore explained, are provided with suitable means forextinguishing the are. In this way, the normal contact surfaces of theterminals 10 and 6 are preserved from the injuries which would otherwiseoccur by reason of the arcs.

A relay switch for governing the control circuits comprises an arm 17pivotally supported upon a bracket 18, and having at one end aninsulating block 19 provided with contact segments 20, that are engagedby a plurality of contact fingers 21.. The opposite extremity of the arm17 is slotted and engages a pin 22 that projects from the rod 2. In thisway, the motion of the rod is transmitted to insulating block 19 throughthe rocking arm 17.

The electro-magnet 9, as shown, is constructed in accordance with adesign described in my co-pending application Serial No. 253,638, filedApril 3, 1905, and patented April 30, 1907, 851,663, but may, of course,be of any suitable c nstruction.

I claim as my invention:

1. In an electric circuit interrupter, the combination with. anactuating rod, a movable bridging contact member pivotally mountednearits central point upon the said rod, a pair of stationary contactmembers to be engaged by said movable member, a link and a flexibleshunt between one of the sta tionary members and the movable member,

'. of means for effecting final engagement of the movable member withone of said stationary members as the switch is closed and for effectinginitial separation of said mem bers as the switch is opened, said meanscom-- prising a spring and a stationary guide rod therefor having a stopat its free end.

2. The combination with an actuating rod,

a movable bridging contact member pivotally mounted thereon, and a pairof stationary contact members to be engaged by said movable member, of alink and a flexible shunt between one of the stationary members and themovable member, and means for effecting final engagement of the movablemember with said stationary member as the switch is closed 3. Thecombination with an actuating rod, and a movable bridging contact memberpivotally mounted near its central point upon said rod, of a pair ofstationary contact members to be engaged by said movable member, alinlt'and a flexible shunt between one of the stationary members and themovable member, and means for effecting final engagement and initialseparation, of the movable member and said stationary memher, said meanscomprising a spring which the shunted stationary member.

4. In an electric circuit interrupter, the comb1nat1on with an actuatmgrod, movable bridging contact member pivotally mounted thereon, a pairof stationary contact members engaged by said movable member and a linkand a flexible shunt between one of the stationary members and themovable member, of means for effecting final. engagement and initialseparation of the movable member and said stationary member, said meanscomprising a spring which tends to separate the movable member from theshunted stationary member and a stationary guide rod having means forlimiting the motion of one extremity of the movable member.

5. The combination with a movable bridging contact member, an actuatingdevice upon which said member is pivotaliy sup-- ported at a pointbetween its contact portions and a pair of stationary contact terminals,of a spring acting against one end only of the movable member to turn itupon its pivot away from the corresponding sta tends to separate themovable member front tionary contact terminal in order to insure finalengagement andwinitial separation of said parts. a

6. In an electric circuit interrupter, the combination With a bridgingcontact mem-' her, an operating member upon which said bridging memberis pivotally supported between its contact portions, and a pair ofstationary contact terminals to be engaged by said bridging member, of arepelling spring interposed between one end of the bridging member and astationary part in order to insure a final engagement and an initialseparation of said end and the corresponding stationary contactterminal.

7. In an electric circuit interrupter, the combination with a bridgingcontact member, an operating member upon which said bridging member ispivotally mounted between its contact portions, and a pair of stationarycontact members to be engaged by said bridging member, of means foroft'ecting' final engagement andinitial-separation of the bridgingmember and one of said stationary contact members, said means comprisinga spring" which tends to separate the bridging member from saidstationary member and a stationary guide rod therefor which limits themotion of one extremity of the bridging member. v

8. In an electric circuit interrupter, the combination with a pivotallymounted movable bridging contact member and a pair of stationary contactmembers to be engaged by said movable member, ofimeans for offectingfinal engagement and initial separation of the movable member and one ofsaid stationary members, said means comprising a spring which tends toseparate the movable member from the said stationary member and. astationary guide rod therefor which limits the motion of one extremityof the movable member and supports the s nking between. said extremityand a suitprojectiou on said stationary Contact member.

9. ln electric switch, the combination b a pair of stationary contactterminals, brir 'ing contact member, a supporting ctnating device uponwhich said bridg' is pivotally mounted between its atact portions, and-aspring interposed between one end of the bridging member and thecorresponding contact terminal to turn said member upon its pivot andmove said end away from said contact terminal.

10. In an electr' l switch, the combination with a pair of stationarycontact terminals, of a bridging contact bar, a supporting and actuatingrod upon which said bar is piv otally mounted between its contactportions,

a flexible shunt around one of the stationary 12. In an electricswitch/, the combination with a pair of stationary cont-act terminals, abridging; contact bar, a rod upon which said bar is pivoted between itscontact portions, and means for actuating said rod to make and break thecircuit, of a flexible shunt around one of said terminals, a springtending to separate one end of said bar from the shunted terminal and astop for limiting the movement of separation.

13. The combination with a movable contact member, a stationary contactterminal opposite one end of said movable contact member and a stopopposite the other end, an actuating device upon which said more her ispivotally supported at a point between its ends, and a, spring actingagainst one end only of thamovable member to turn it upon its pivot awayfrom the etc in order to insure final engagement and initial sepa rationof the movable member and the step.

In testimony whereof, l have hereunto subscribed my name this 24th. dayof February, 1906. v

RAY P. JAGKSGN.

. Viitnesses:

R. B. Inseam, BIEZNE}: Hines.

